When did dual-classing become so common in D&D? It seems like it’s the norm now.
My players rarely if ever multiclassed. In 3E PRCs were the shizit.
3E may have suffered from scaling issues and bloat but 4E sucked all the fun and creativity out of the game for me. No interest in bothering with 5E after that. Both 4E and 5E strike me as games designed by low-int DMs who could never figure out a way to challenge players beyond level 4. "Oh no, my players defeated my awesome ambush by flying over it!" This was the legacy of the low-XP
bug that was added in 2E.
I've pointed this out many times but it bears repeating, 2E was often a very low-powered game because people were playing it wrong. The XP tables were designed to use GP = XP, but the actual rule for XP for treasure was listed as "optional." People assumed this meant 'non-standard,' and they played without it. The rules said if you didn't use treasure XP then you should use quest XP. But this was
also an 'optional' rule, so many games used neither. As a result your only source of XP in 2E was combat, which was a paltry 15 xp per goblin, divided 4+ ways, and you needed 2000 to level. Yikes.
Many such 2E games never made it past levels 2-4. This gave D&D its reputation for glacial leveling and grueling fights. On top of that, a way overblown reaction to 'monty haul' led to DMs treating +1 daggers as one-of-a-kind ultimate artifacts. 2E was a boring AF game at most tables.
When 3E came along they revamped the XP system so players could actually reach level 5, and so many DMs were like "that's PoWErGaMIng!" They didn't enjoy players having access to spells and powers that let them, you know,
win fights. The urge to nerf was so insane I saw 3E games where half the classes, spells, feats, and magic items were all banned.
Yes, 3E could get pretty crazy, and some players got so cheesy with their builds it could ruin the fun for the rest of the players. The real problem in 3E was the difference between an optimized build and someone who just took whatever. But I never once had a problem challenging my PCs with 3E.
4E and 5E are an attempt to bring back the suck. Make the game slower, more boring, fewer level ups, tightly restricted magic and items, hard limits with no justification, and keep the players on the ground so they can't fly over the DM's super cool ambush he spent all night on.